Multilayer Pattern Displacement Measurement Using Charged Particle Radiation
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Solution Overview
Problem
Existing methods for evaluating semiconductor device performance fail to accurately measure displacement between multilayer patterns, which is crucial for assessing superimposition precision in semiconductor devices with complex structures.
Innovation Solution
A method and apparatus that measure the distance between line segments of design data and charged particle radiation images for both upper and lower layers, allowing for the detection of superimposition displacement by comparing these distances to evaluate the precision of pattern superimposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If edge detection and comparison methods are used to measure pattern deformation, then manufacturing precision can be evaluated, but displacement between multilayer patterns cannot be measured
Solution Approach 1:
The patent segments the measurement process into distinct steps: first detecting edges of the subject pattern, then detecting corresponding edges of the reference pattern, and finally calculating displacement based on detected edge positions. This segmentation enables the system to handle complex multilayer displacement measurements by breaking them into manageable detection and calculation stages
Solution Approach 2:
The patent introduces an intermediary calculation process that uses detected edge positions to determine displacement. By using the detected edges as intermediate reference points, the system can evaluate both single-layer deformation and multilayer displacement, thus resolving the contradiction between measurement precision and measurement versatility
2Measurement precision
If design data is used as reference for pattern evaluation, then ideal shape comparison is possible, but superimposition precision between layers cannot be assessed
Solution Approach 1:
The patent merges the advantages of design data reference (ideal shape) with actual pattern detection (real positions) by superimposing detected pattern edges onto design data. This combination allows simultaneous evaluation of both pattern shape accuracy and layer superimposition precision, resolving the contradiction between measurement precision and manufacturing precision assessment
3Measurement precision
If single-layer pattern detection is performed, then edge accuracy can be measured, but multilayer superimposition displacement cannot be detected
Solution Approach 1:
The patent extends the measurement from single-layer edge detection to multilayer displacement detection by adding a temporal and spatial dimension. The system detects edges at different layers and calculates displacement between them, effectively moving from two-dimensional edge detection to three-dimensional multilayer position analysis, thus resolving the detection difficulty
Data Source
AI summary
An evaluation method and apparatus is provided for evaluating a displacement between patterns of a pattern image by using design data representative of a plurality of patterns superimposed ideally. A first distance is measured for an upper layer pattern between a line segment of the design data and an edge of the charged particle radiation image, a second distance is measured for a lower layer pattern between a line segment of the design data and an edge of the charged particle radiation image; and an superimposition displacement is detected between the upper layer pattern and lower layer pattern in accordance with the first distance and second distance.